LixV2O5 nanobelts for high capacity lithium-ion battery cathodes

5–10 μm long, typically 200–300 nm wide, and several nanometers thick Li_xV₂O₅ (× ～ 0.8) nanobelts with the δ-type crystal structure were synthesized by a hydrothermal treatment of Li⁺-exchanged V₂O₅ gel. When dried at 200 °C under vacuum prior to electrochemical testing, the as-prepared nanobelts underwent the well-known δ → ε → γ-phase transition giving a mixture of ε and γ phases as a nanocomposite electrode material. Such a simple preparation procedure guarantees a yield of material with drastically enhanced initial discharge specific capacity of 490 mAh/g and great cyclability. The enhanced electrochemical performance is attributed to the complex of experimental procedures including post-synthesis treatment of the single-crystalline Li_xV₂O₅ nanobelts.